Leeds, 1957: When enquiry agent Dan Markham and his new partner, retired Detective Sergeant Baker, take on a missing persons case, a simple matter turns into a murder investigation when a body is recovered from the River Aire. Nothing is what it seems. The dead man is an East German. A defector or spy? More mysterious deaths follow and the investigation takes a deadly turn as the pair try to track down a ruthless Russian assassin and Markham finds himself dragged into the heart of a Cold War - in Leeds.